Display apparatus



July 21, 1942- A J. F; FREEDMN Als-rm.

DISPLAY APPARATUS Filed Dec. 1,` 1939 5 Sheets-Sheet 1 July 2l, 1942.

J. F. FREEDMAN-E'r AL IJISPLAY-A APPARATUSv Filed Dec.V 1, 1939 ssheets-sheet 2 July 21 1942l l J. F. FREEDMAN ETA. 2,290,280

DISPLAY APPARATUS Filed Dec. l, 1939 3 .Sh'eets-Sheet I5 TW ow iWITNESSES:

ATTORNEY Patented July 21, 1942 area-28e DISPLAY APPARATUS Julius F.Freedman and Abner YAflyer, Pittsburgh, Pa.

Application December 1, i939, Serial No. 307,150

Claims.

Our invention relates to display apparatus and has particular relationto luminous signs for displaying a dynamic or traveling pattern.

In traveling signs constructed in accordance with the teachings of theprior art, of which We are aware, the pattern is produced byy an arrayof incandescent lamps which are selectively energized. To dissipate theheat which is produced by the iilaments so that it is harmless, the lampenvelopes are preferably substantially spherical. Incandescent lampswith which an elongated luminous column is produced are available butbecause of the diiculties involved in the design and construction ofsuch lamps, their cost for sign purposes is prohibitive. The sphericallamps which are used are necessarily relatively small and, therefore,for a sign of ordinary structure, a large number `of lamps are required.In one case of which We are aware, a traveling sign for conveyingmessages has 22,000 lamps.

The excessive number of illuminating units is undesirable because of theservicing demands that it imposes. Numerous failures necessarily occurcontinually among so great'a multitude of lamps and continuousreplacement .is required. This condition is aggravated bythe factthatlamps which are intermittentlyturned `on and ofi have a relatively shortlife. A more serious consequence of the numerous lamps is 'aconsequenceof the condition that a selective contact element must be associatedwith each lamp. The number of contacts which must, therefore, be used islarge and the labor involved in servicing the contacts is prodigious. Inaddition, a large space must be set aside for mounting the contactboard. In the case ofthe 22,000 lamp sign, there are 22,000 contacts.

Another disadvantage involved in the'use of incandescent lamps toproduce the luminosity in a traveling sign arises from the fact that theradiation emitted from an incandescentlament does not correspond to theinstantaneous current ilow through the'lament. There is a substantialtime-lag and When'the'current flowthrough the iilament is discontinued,'-thellamp continues to emit illumination for-a short 'time -intervaLThe display produced by 'a--sign made uplo'f incandescent lamps is,"therefore, 4some'vvhat vvhazy.

In many situations, itis desirablethatthe`elee ments of the patternproduced-shall vhavefdouble outlines. For example, where `Words L'aredisplayed, -double line letters are often preferred to single lineletters. To pIOduCeadOubleline vdisplay with an array oisphe'ric'alincandescent lamps is not practicable because or" the 'dinicultiesinvolved in properly selecting the contacts to be operated. Incandescentlamps bent into substantially closed curves, such as rectangles, are notavailable. Such lamps, even if they could be manufactured, would have arather short life because the lament as it sags when heated would fusethrough the glass envelope, particularly at the corners.

`It is accordingly an object of our invention to provide a sign invvhichthe number of luminous units shall be a minimum.

Another object of our invention is to minimize to space necessary forthe selective contacts of a luminous 'sign of the dynamic type.

A further object of our invention is to provide a dynamic luminoussignof simple and inexpensive structure.

Still Vanother object of our invention is to provide a dynamic sign thatshall require Va minimum of servicing.

A still further object of our invention isgto provide a dynamic sign,the cost of operation of which shall be a minimum.

Amore specific object of our invention is to provide a luminous sign fordisplaying configurations such as numbers or letters having a doubleoutline.

Another specic object of our invention is to provide a luminous sign inwhich the outlines of the configurations displayed shall bemulticolored.

A further specic object of our invention is to simplify the controlapparatus used in producing a multi-colored luminous dynamic display.

An ancillary object of our invention is to providean array of selectivecontacts for the control of 'ai dynamic luminous display that shalloccupy a relatively small space.

Another ancillary object' of our invention is to provide areliableselective control system for a dynamic sign.

An incidental object of our invention is to provide an electricdischarge sign Without using glow discharge tubes of numerous differentstructures.

More concisely stated, it is an object of `our invention to provide asign, for producing a traveling luminous pattern, that shall require arelatively small number of luminous units and a relatively smallselective contact system of simple structure.

In accordance with our invention, a luminous sign made up of arectangular array of glow discharge devices of similar structure isprovided. The form of the glow discharge devices used in our signdepends on the character of thel display desired. Where a simple singleline display is involved, each glow discharge device may be simply alongitudinal envelope having electrodes at its ends, and provided withan attenuated ionizable medium corresponding to the color desired. Whena suitable potential is impressed between the electrodes, a luminouscolumn corresponding to the length of the tube is produced. The tube maybe of substantial length since there is no limitation as to thedissipation of heat. We have found, for example, that a tube 2 feet longmay be used. Such a tube produces the same visual eiect as a column oflamps two feet long and when the tube is used, substantially fewercontacts are necessary than for lamps.

Where a double line display is desired, each luminous unit is a tube inthe form of a substantially closed plane curve such as a rectangle forexample. When an array of such luminous units is energized selectively,a double line display is produced. In this case, also, the dimensions ofthe tube may be substantial. In a sign three feet high and twenty feetlong according to our invention which we have found to operatesuccessfully, 280 rectangular tubes are used. Each tube is six incheshigh by four inches long. For a similar sign three hundred feet long,the number of luminous units required is 5200. The dimensions of thelast mentioned sign are comparable to the lamp sign in which 22,000lamps are required. The selective control arrangement required inaccordance with our invention is thus substantially smaller than thatrequired for prior art signs. Still further sainng in space and numberof contacts may be eiected in the practice of our invention byincreasing the dimensions of the illuminating units.

The power consumption of our sign is also considerably smaller than thatof an incandescent lamp sign. The usual illuminating unit according toour invention passes .015 ampere at 2000 volts; i. e., its power ratingis 30 watts. The units of a corresponding lamp sign certainly have ahigher power rating and in addition the number of units in the latter isseveral times as great as in our sign.

Finally it is to be noted that the height of a signaccording to ourinvention may be increased by the simple expedient of increasing theheight of the illuminating units. In the lamp signs additional lampsmust be added.

For more elaborate displays, each unit may be composed of a plane curvetube, in the center of which one or more longitudinal tubes aredisposed. The individual tubes of each unit may be lled with differentionizable media and thus a multi-colored display is achieved.

Regardless of the character of the sign, one of the significant featuresof our invention arises from the fact that it is made up of a largenumber of units of similar structure. Prior art electric discharge signsrequire a large number of tubes of different structures.

To control the excitation of the luminous units, we provide a pneumaticsystem. The contacts associated with the various units are actuated bydiaphragms, the movement of which is selectively controlled from asystem of suction tubes. The latter, in turn, are selectively opened andclosed to the atmosphere by a tape which is perforated to correspond tothe desired display.

The novel features that we consider characteristic of our invention areset forth with particularity in the appended claims. The inventionitself, however, both as to its organization and its method ofoperation, together with additional objects and advantages thereof, willbest be unclerstood from the following description when read inconnection with the accompanying drawings, in which:

Figure l is a View in iront elevation showing a preferred embodiment ofour invention;

Fig. 2 is a View in end elevation of thc embodiment shown in Fig. 1;

Fig. 3 is a View in front elevation of an illuminating unit used in thepractice of our invention;

Fig. 4 is a view in side elevation of the illuminating unit shown inFig. 3;

Fig. 5 is a view in front elevation ol another unit used in the practiceof our invention;

Fig. 6 is a view in side elevation of the illuminating unit shown inFig. 5;

Fig. 7 is a diagrammatic view showing a section of a sign in accordancewith our invention and the control equipment for operating the sign; and

Fig. 8 is a View in perspective showing a control system for a sign inaccordance with our invention.

The apparatus shown in Figs. l to 7 comprises a Vertical support 9 ofthe form customarily used in travelling signs on which an array ofilluminating units II are mounted. Where words are to be displayed, asin the case in the Fig. 1 structure, the array should be at least veunits deep and its length in units should correspond to the character ofthe display desired. At least five illuminating units are necessaryalong the vertical dimension to properly display such letters as M andX.

Each illuminating unit II comprises a glow discharge tube I3 in the formof a rectangle and a linear tube I5 disposed in the center of the regionbounded by the rectangle. The envelope of the linear tube I5 is formedof a hollow bar of a transparent insulating material such as glass whichis bent over at its ends so that a C-shaped structure results.Electrodes Il are sealed through the bent over projections I9. Duringthe course of its construction, the tube is exhausted and an ionizingmedium, such as an inert gas or mercury at a low pressure is providedtherein. The envelope for the rectangular tube I3 is formed of a hollowbar of a transparent insulating material. The ends of the bar are firstbent at right angles as in the case of the linear tube. Thereafter thebar is bent at right angles to the bent over end projections 2| at threepoints which are so selected that the projections 2| lie adjacent toeach other at right angles to the plane of the substantially closedrectangle which is bounded by the tube. Electrodes 23 are sealed throughthe projections 2I and a suitable ionizing medium is provided within theenvelope after it has been exhausted.

Preferably, the radiant energy emitted from the linear tube I5 when itis energized should be of a diierent color from that emitted from therectangular tube I3. To achieve this object, different ionizing mediaare used in the tubes. For example, mercury may be used in the lineartube I5 to produce a blue discharge while neon may be used in therectangular tube I3 to produce an orange-red discharge.

The tubes I3 and I5 are mounted on the support 9 with their right angleprojections I9 and 2I, respectively, extending horizontally through thesupport. Conductors .25.and 21, in each case, interconnect theelectrodes I9 and 23, lrespectively, and a transformer 29 through whichthe units are energized. Each transformer 29 comprises a primary 3| andaplurality of second-aries 33 and 35. The electrodes |1 of the lineartube I5 are connected, in each case, across one of the secondaries 33while the electrodes 23 of the corresponding rectangular tube I3 areconnected across another secondary 35.

The tubes I3 and I5 are energized by connecting the primaries of thecorresponding transformers 29 across the line conductors l31 of a powersource (not shown) which may be of the usual commercial, (S-cycle type.For this purpose, a contact device 39 is associated with each of theprimaries 3|. The movable element 4| of the contact device 39 isactuated by a rod 43 secured to a movable diaphragm 4.5 and engages ordisengages the cooperative xed element 41 in accordance with themovement of the rod. The circuit for each illuminating unit I I extendsfrom one of the line conductors 31 through the fixed element 41 of thecorresponding contact device 39, the movable element 4| of the contactdevice,

the primary 3| of the transformer 29 to the other line conductor 31. InFig. '1, the circuits through the two left hand units are shown asclosed and the circuit through the upper right hand unit is shown asopen.

The excitation of the illuminating units is controlled from a suitablyperforated tape 49. 'Ihe tape 49 may be of ordinary paper, a celluloseweb, or it may be of a paper made up of a phenolic condensation product.uous reel and rides on horizontal rollers 53 journaled in blocks 55secured to a ring shaped base 51. The tape is held on the reel betweenhorizontal strips 59 pivotally secured to studs 6| extending from theouter blocks 55 and vertical .f

flanged rollers 63 journaled in the base 51. The strips 59 may be turnedabout the studs 6| to permit insertion or removal of the tape 49.

The tape 49 is advanced through a gate 64 by a plurality of motor-drivenfriction rollers 65 and 61 between which it is compressed. The lowerroller 61 is mounted on xed bearings 69 and is rotated by a motor 1|.The upper roller 65 is mounted in bearings 13 slidable radially relativeto the lower roller 61 and is urged towards the lower roller by springswhich engage the bearings 13.

The tape 49 is advanced from the inner periphery of the toroid withinthe reel 5| over deflecting idlers 11 which are mounted on the base 51at proper angles to the base. 64 it passes over a fixed idler 19 mountedon the the gate support and under a gravity idler 8| pivotally supportedfrom the fixed idler. The gravity idler 8| maintains the tape taut as itadvances through the gate. On leaving the friction rollers 65 and 61,the tape 49 passes into ia loop 83 whence it passes over guiding idlers85 and is wound on the outer periphery of the toroid.

'Ihe gate 64 comprises a perforated guiding block 81 adjacent to which aperforated supporting block 89 is removably mounted. The blocks 81 and89 may be mounted on suitable brackets which are not shown because theydo not concern the present invention and the movable block 89 may besupported, hinged or slidable on the brackets in the same manner as ina. motion picture gate. The guiding block 81 is provided withlongitudinal flanges 9| which limit the lateral It is wound on a contin-Near the gate movement of the tape 49. The supporting block 89 yisprovided with a central longitudinal raised portion 93 rof the samewidth as the recessive portion of the guiding .block 81. When the gates81 and 89 are disposed adjacent to each other,

the flanges 9| extend over the raised portion 93 and :between them thereis a narrow slot through which the tape advances. The supporting block89 may be disengaged from the yguiding block 81 to facilitate thethreading of the tape 49 in the apparatus.

The perforations 95 and 91 in the block 81 and 89, respectively, arecoextensive. They are arranged in a pattern corresponding in form to theilluminating units The openings 95 and 91 are thus ve deep and theirnumber in length is equal to the number of illuminating units along thecorresponding dimension.

From each of the openings 95 in the guiding block 81 a tube 99 extends.Each tube 99 lcommunicates with an air-tight container |8I, one surfaceof which is the flexible diaphragm 45 to which the rod 43 is secured.The containers |8| are, in turn, all in communication with a conductor|03 leading from a suction pump |95 of any well known structure, whichis operated by the motor 1'|, whereby the tape is advanced. Thediaphragm container I0| is, of course, only one of a number ofcontrivances which may be used in the practice of our invention. Thecontainers |0| may, for example, be replaced by Sylphons or bellows ofsuitable structure.

As the tape 49 advances between the perforated blocks 81 and 89, certainof the perforations 95 and 91 in the blocks are maintained closed whileothers are open because perforations |01 in the tape coincide withopenings in the blocks. When an unperforated portion of the tape isdisclosed between the perforations 95 and 91 in the blocks 81 and 89,respectively, the pump |95 withdraws the air from the correspondingcontainer |0| and the corresponding diaphragm 45 recedes, opening thecorresponding contact 39. When a perforation in the tape is coincidentwith coextensive openings in the blocks, air flows into thecorresponding container |9| and the diaphragm 45 is urged outwardly sothat the corresponding contact 39 is closed. The transformers 29 and theilluminating units II with which they are associated are thus energizedor deenergized in accordance with-the positions of the perforations inthe tape and a display corresponding to the perforations is produced.

While the use of the suction contact control has many advantages in thepractice of our invention, our invention in its broader aspectsvcontemplates the use of contact controls of other types. For example,pressure contact control may be applied or the contact rods may bemechanically actuated by a tape which is in direct engagement with theirfree ends.

The suction contact control may, in accordance with the broader aspectsof our invention, be used with illuminating units of other types thanthose disclosed and such use is contemplated as falling within ourinvention.

Although we have shown and described certain specic embodiments of ourinvention, we are fully aware that many modifications thereof arepossible. VOur invention, therefore, is not to be restricted exceptinsofar as is necessitated. by the prior art and by the spirit of theappended claims.

' We claim as our invention:

1. In combination an array of elongated glow vdischarge devices ofsimilar structure arranged in columns and rows each of said devicesbeing capable of producing a luminous column when energized and meansfor selectively energizing said devices in a predetermined sequence toproduce the effect of a movingr display, a plurality of said devicesfrom different columns and rows of said array being combined to produceeach single separately identifiable element of said display.

2. In combination an array of elongated glow discharge devices ofsimilar structure arranged in columns and rows with their long dimensionextending vertically, each of said devices being capable of producing aluminous vertical column when energized and means for selectivelyenergizing said devices in a predetermined sequence to produce a movingdisplay of letters, numbers and iigures, a plurality of said devicesfrom different columns and rows of said array being combined to produceeach letter, number or figure of said display.

3. In combination an array of elongated glow discharge devices ofsimilar structure arranged in vertical rows of at least five deviceswith their long dimension extending vertically, each of said devicesbeing capable of producing a luminous vertical column when energized andmeans for selectively energizing said devices in a predeterminedsequence to produce a moving display of letters, numbers and iigures, aplurality of said devices from diiferent columns and rows of said arraybeing combined to produce each letter, number or figure of said display.

4, In combination an array of glow discharge units arranged in columnsand rows each of said units consisting of a plurality of glow dischargedevices, at least one of which is elongated, a transformer having asingle primary and a plurality of secondaries corresponding in number tothe devices in each of said units associated with each unit, means forconnecting a secondary of each of said transformers to a glow device ofeach of said units and means for selectively energizing the primaries ofsaid transformers to produce a luminous display, a plurality of saidunits from different columns and rows of said array being combined toproduce each single separately identifiable element of said display.

5. In combination an array of elongated glow discharge devices ofsimilar structure arranged in columns and rows each of said devicesbeing capable of producing a luminous column when energized and meansfor selectively energizing said devices to produce a moving display, aplurality of said devices from different columns and rows of said arraybeing combined to produce each single, separately identifiable elementof said display.

'6. In combination an array of glow discharge units arranged in columnsand rows each of said units consisting of a plurality of glow dischargedevices, at least one of which is elongated, a transformer having asingle primary and a plurality of secondaries corresponding in number tothe devices in each of said units associated with said unit, means forconnecting a secondary of each of said transformers to a glow device ofeach of said units and means for selectively energizing the primaries ofsaid transformers in a predetermined sequence to produce a luminousmoving display, a plurality of said units from different columns androws of said array being combined to produce each separatelyidentifiable element of said display.

7. In combination an array of glow discharge units arranged in columnsand rows each of said units consisting of a plurality of glow dischargedevices, at least one of which is elongated, each of the devices of eachof said units having a different onizable atmosphere so that when saiddevices are energized each unit is a luminous configuration of aplurality of colors, a transformer having a single primary and aplurality of secondaries corresponding in number to the devices in eachof said units associated with said unit, means for connecting asecondary of each of said transformers to a glow device of each of saidunits and means for selectively energizing the primaries of saidtransformers in a predetermined sequence to produce a luminous movingdisplay, a plurality of said units from different columns and rows ofsaid array being combined to produce each separately identifiableelement of said display.

8. In combination an array of glow discharge devices of similarstructure arranged in columns and rows each of said devices comprisingan envelope having at least one bend therein and when energized capableof producing a luminous band of corresponding form and means forselectively energizing said devices in a predetermined sequence toproduce a luminous moving display, a plurality of said devices fromdifferent columns and rows of said array being combined to produce eachsingle, separately identifiable element of said display.

9. In combination an array of glow discharge units arranged in columnsand rows each of said units consisting of a plurality of glow dischargedevices, at least one of which is elongated, corresponding devices ofdifferent units being of the same structure, a transformer having asingle primary and a plurality of secondaries corresponding in number tothe devices in each of said units associated with said unit, means forconnecting a secondary of each of said transformers to a glow device ofeach of said units and means for selectively energizing the primaries ofsaid transformers in a predetermined sequence to produce a luminousmoving display, a plurality of said units from diiferent columns androws of said array being combined to produce each separatelyidentifiable element of said display.

10. In combination an array of glow discharge devices of similarstructure arranged in columns and rows each of said devices comprisingan envelope substantially in the form of a closed plane curve and whenenergized capable of producing a luminous band in the form of a planecurve and means for selectively energizing said devices in apredetermined sequence to produce a luminous moving display of doublelined letters and numbers, a plurality of said devices from differentcolumns and rows of said array being combined to produce each letter ornumber of said display.

1l. In combination an array of glow discharge devices of similarstructure arranged in columns and rows each of said devices comprisingan envelope substantially in the form of a closed plane curve and whenenergized capable of producing a luminous band in the form of a planecurve and means for selectively energizing said devices to produce aluminous ,display of double lined letters and numbers, a plurality ofsaid devices from different columns and rows of said array beingcombined to produce each letter or number of said display.

l2. In combination an array of glow discharge units arranged in columnsand rows each unit consisting of a glow discharge device comprising anenvelope substantially in the form of a closed plane curve within whicha glow discharge device comprising a substantially linear envelope isdisposed, each unit when energized producing a luminous plane curve witha luminous band therein, and means for selectively energizing said unitsto produce a luminous display, a plurality of said units from differentcolumns and rows of said array being combined to produce each single,separately identiable element of said display.

13. In combination an array of glow discharge units arranged in columnsand rows each unit consisting of a glow discharge device comprising anenvelope substantially in the form of a closed plane curve within whicha glow discharge device comprising a substantially linear envelope isdisposed, the ionizable gases within said curve and linear envelopesbeing different, each unit when energized producing a luminous planecurve with a luminous band of a color diierent than the color of saidcurve therein, and means for selectively energizing said units toproduce a luminous display, a plurality of said units from differentcolumns and rows of said array being combined to produce each single,separately identiable element of said display.

14. In combination an array of glow discharge units arranged in columnsand rows 'ach unit consisting of a glow discharge device comprising anenvelope substantially in the form of a closed plane curve Within whicha glow discharge device comprising a substantially linear envelope isdisposed, the ionizable gases within said curve and linear envelopesbeing dilerent, each unit when energized producing a luminous planecurve with a luminous band of a color different than the color of saidcurve therein, and means for selectively energizing said units in apredetermined sequence to produce a luminous moving display, a,plurality of said units from different columns and rows of said arraybeing combined to produce each single, separately identifiable elementof said display.

15. Apparatus according to claim 12, characterized by the fact that witheach unit a transformer having a primary and at least two secondaries isassociated, said secondaries being connected each to a glow dischargedevice of the corresponding unit and by means for selectively supplyingcurrent to the primaries of said transformers to selectively energizesaid units.

JULIUS F. FREEDMAN. ABNER A. BYER.

